linux/arch/m32r
Francis Yan 1c885808e4 tcp: SOF_TIMESTAMPING_OPT_STATS option for SO_TIMESTAMPING
This patch exports the sender chronograph stats via the socket
SO_TIMESTAMPING channel. Currently we can instrument how long a
particular application unit of data was queued in TCP by tracking
SOF_TIMESTAMPING_TX_SOFTWARE and SOF_TIMESTAMPING_TX_SCHED. Having
these sender chronograph stats exported simultaneously along with
these timestamps allow further breaking down the various sender
limitation.  For example, a video server can tell if a particular
chunk of video on a connection takes a long time to deliver because
TCP was experiencing small receive window. It is not possible to
tell before this patch without packet traces.

To prepare these stats, the user needs to set
SOF_TIMESTAMPING_OPT_STATS and SOF_TIMESTAMPING_OPT_TSONLY flags
while requesting other SOF_TIMESTAMPING TX timestamps. When the
timestamps are available in the error queue, the stats are returned
in a separate control message of type SCM_TIMESTAMPING_OPT_STATS,
in a list of TLVs (struct nlattr) of types: TCP_NLA_BUSY_TIME,
TCP_NLA_RWND_LIMITED, TCP_NLA_SNDBUF_LIMITED. Unit is microsecond.

Signed-off-by: Francis Yan <francisyyan@gmail.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-30 10:04:25 -05:00
..
boot m32r: fix build warning about putc 2016-07-15 14:54:27 +09:00
configs
include tcp: SOF_TIMESTAMPING_OPT_STATS option for SO_TIMESTAMPING 2016-11-30 10:04:25 -05:00
kernel mm: replace access_process_vm() write parameter with gup_flags 2016-10-19 08:31:25 -07:00
lib m32r: add __ucmpdi2 to fix build failure 2016-07-26 16:19:19 -07:00
mm mm: do not pass mm_struct into handle_mm_fault 2016-07-26 16:19:19 -07:00
oprofile
platforms
Kconfig lib/GCD.c: use binary GCD algorithm instead of Euclidean 2016-05-20 17:58:30 -07:00
Kconfig.debug
Makefile